I have had my D40 for a little over a year now, and I have accumulated 4 lenses (18-55kit, 55-200, tamron 90mm, and 50mm f/1.8), and an SB-600. I was wondering if there is a good upgrade from the 18-55mm kit lens, possibly something a bit faster that goes a bit wider maybe? I guess quality is my main concern, I know the 18-55 is a good lens, but I was looking for something that, if I move to a different body, I could take with me. I dont even know where to start looking. If everyone could just throw some ideas out, that would be great.